Blasting apparatus

ABSTRACT

A melting/vaporization substance  2  is melted and vaporized by supplying an electric energy of a predetermined amount from an electric energy supply circuit to the melting/vaporization substance  2 . An explosive blasting substance  3  is exploded by a phenomenon caused in a process of melting and vaporization of the melting/vaporization substance  2 , so that a to-be-blasted object  4  is blasted by that explosive force.

TECHNICAL FIELD

This invention relates to a blasting apparatus for blasting ato-be-blasted object such as a concrete construction or a rock base bymelting and vaporizing a melting/vaporization substance (e.g., metallicfine wire) by supplying electrical energy for a short time and thenexploding an explosive blasting substance by a phenomenon of a processaccompanying the vaporization.

BACKGROUND ART

According to the prior art, as a blasting apparatus for blasting aconcrete construction or a rock base, there is a type which includes adynamite and a detonator in which explosive powder is filled internallyas a means for exploding the dynamite.

For the dynamite, an explosive powder having a poor sensitivity which isnot easy to explode even if some shock is applied or a flame flashesover is used so as to secure safety of handling. Because of this, thedetonator contains an explosive powder which is relatively easy toexplode. By exploding the explosive powder contained in the detonator bya fire or electric spark, the explosive powder contained in the dynamiteis exploded by a caused shock. However, because an explosive powderrelatively easy to explode is contained in the detonator, if leakagecurrent from machines disposed around a stock yard or current caused bysurge or lightning is supplied to the detonator, there is a danger thatthe detonator explodes.

Accordingly, an object of the present invention is to provide a blastingapparatus capable of solving the aforementioned problem.

DISCLOSURE OF INVENTION

The present invention provides a blasting apparatus in which anexplosive blasting substance is filled in a blasting container,melting/vaporization substance which is melted and vaporized rapidlywhen an electric energy of a predetermined amount is supplied theretofor a short time is provided in the blasting substance so that themelting/vaporization substance is exposed, an electric energy supplycircuit for supplying the electric energy to the melting/vaporizationsubstance is provided, and the blasting substance is exploded by aphenomenon caused in a process of melting and vaporization of themelting/vaporization substance so as to blast a to-be-blasted object bythe explosive force.

In a structure of the present invention, when an electric energy of apredetermined amount is supplied from an electric energy supply circuitto a melting/vaporization substance, the melting/vaporization substanceis melted and vaporized rapidly. The explosive blasting substance isexploded by a phenomenon in a process of melting/vaporization of themelting/vaporization substance so as to blast a to-be-blasted object bythe explosive force. Further, even if leakage current is supplied fromsurrounding devices, as long as an electric energy enough for themelting/vaporization substance to be melted and vaporized is notsupplied, the blasting substance is not exploded, thereby improving thesafety in handling the blasting apparatus.

Further, the present invention provides a blasting apparatus in which anexplosive blasting substance is filled in a blasting container mountedin a mounting hole formed in a to-be-blasted object, a metallic finewire which is melted and vaporized rapidly when an electric energy of apredetermined amount is supplied thereto for a short time is provided inthe blasting substance such that the metallic fine wire is exposed, anelectric energy supply circuit for supplying the electric energy to themetallic fine wire is provided, and the blasting substance is explodedby supplying the electric energy to the metallic fine wire for a shorttime so as to melt down the wire, so that the to-be-blasted object isblasted by the explosive force.

In a structure of the present invention, when an electric energy of apredetermined amount is supplied from an electric energy supply circuitto a metallic fine wire, the metallic fine wire is fused(melted/vaporized) so that short-circuit occurs, and the blastingsubstance catches fire and then is exploded. The to-be-blasted object isblasted by this explosive force. Further, even if leakage current occursfrom surrounding devices, as long as electric energy enough for themetallic fine wire to be fused is not supplied, the blasting substanceis not exploded. Thus, the safety in handling the blasting apparatus isimproved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a sectional view showing an entire structure of a blastingapparatus according to the present invention, in which a blastingcontainer is mounted in a mounting hole formed in a to-be-blastedobject, and

FIG. 2 is an enlarged sectional view showing a state in which a blastingcontainer is mounted in a mounting hole formed in a to-be-blastedobject.

BEST MODES FOR CARRYING OUT THE INVENTION

The present invention will be described in detail with reference to theaccompanying FIGS. 1 and 2.

In a blasting apparatus 1 according to the present invention, metallicfine wire of copper: Cu formed to be 0.3 mm in diameter asmelting/vaporization substance is vaporized rapidly and a blastingsubstance 3 is exploded by a shock caused by a phenomenon accompanyingthe vaporization, such as discharge, spark, heat and vaporizationexpansion, so as to blast a to-be-blasted object such as a concreteconstruction or a rock base.

As the blasting substance 3, explosives or explosive compounds otherthan the explosives are used. The explosives mean an explosive, a highexplosive and an ammunition as described in the “New Edition: IndustrialExplosives” issued by the Industrial Explosives Society of Japan. Inthis style, blasting powder and smokeless powder are used as explosive,and DDNP, mercury fulminate and the like are used as high explosive.Explosive compounds other than the explosives include, for example,methyl nitrate, nitro-compound, gasoline and the like as described in“Chemical Handbook” complied by the Chemical Society of Japan.

In the blasting apparatus 1 of the present invention, the aforementionedblasting substance 3 is filled in a blasting container 6 mounted in amounting hole 5 formed in a to-be-blasted object 4. An opening side ofthis blasting container 6 is sealed by a lid member 7 and a pair ofelectrodes 8 are inserted through this lid member 7. Ends of theseelectrodes 8 are connected with each other by the aforementionedmetallic fine wire 2 exposed to the blasting substance 3.

As a material of the aforementioned blasting container 6, a non-metalsuch as wood, paper or synthetic resin, or a metal such as aluminum oriron is used.

An electric energy supply circuit 10 is connected to the metallic finewire 2 so as to supply electric energy of a predetermined amount (e.g.,5,000 V) enough to melt and vaporize the metallic fine wire 2.

This electric energy supply circuit 10 comprises a power supply unit 11,a capacitor 14 connected between this power supply unit 11 and bothterminals 8 a, a charge control circuit 12 which is connected betweenthe power supply unit 11 and one side terminal 8 a so as to control thecapacitor 14 to store an electric energy of a predetermined amount(e.g., 400 μF), and a discharge switch 13 which is connected betweenthis charge control circuit 12 and the one terminal 8 a.

The aforementioned blasting apparatus 1 is manufactured by connectingboth ends of the electrodes 8 to each other with the metallic fine wire2, inserting the electrodes 8 through the lid member 7, filling theblasting container 6 with the blasting substance 3, fitting the lidmember 7 to the blasting container 6 to seal the blasting substance 3,and connecting the electric energy supplying circuit 10 to the terminals8a of the electrodes 8. Then, the blasting container 6 is mounted in themounting hole 5 formed in the to-be-blasted object 4.

Then, an electric energy of a predetermined amount necessary for meltingand vaporizing the metallic fine wire 2 is stored in the capacitor 14and the discharge switch 13 is turned on. As a result, theaforementioned electric energy is supplied to the metallic fine wire 2for a short time so that the metallic fine wire 2 is melted andvaporized. By the aforementioned phenomenon accompanying the process ofmelting and vaporization, the blasting substance 3 is exploded. Then,the explosive force of the blasting substance 3 is combined with a shockcaused by the melting and vaporization of the metallic fine wire 2,whereby the to-be-blasted object 4 is securely blasted and made fragile.

According to the present invention, the blasting container is filledwith the blasting substance 3 and instead of the detonator, the metallicfine wire 2 connected to the electrodes 8 is used. Therefore, even ifleakage current occurs from surrounding devices and is supplied to themetallic fine wire 2, as long as electric energy enough for melting andvaporizing the metallic fine wire 2 is not supplied, the blastingsubstance 3 is not exploded. Thus, the blasting apparatus can be handledunder the safety.

Meanwhile, since nitromethane is not exploded until a large shock ofmore than about 70 ton·f/cm² is supplied thereto, an explosive needs beused to explode this nitromethane. Therefore, nitromethane has seldombeen used in the prior art. However, a sufficient shock for explodingnitromethane can be secured by a shock caused when the metallic finewire 2 is melted and vaporized, thereby allowing nitromethane to be usedas the blasting substance 3. By using nitromethane, the same explosiveforce as when dynamite is used can be obtained, so that theto-be-blasted object can be securely blasted and made fragile by thegreat explosive force of nitromethane.

Although an example of using the metallic fine wire 2 as themelting/vaporization substance has been described in the aboveembodiment, it is permissible to use a small piece of metal or aconductive material such as carbon formed in an appropriate shape, asother example of the melting/vaporization substance. When such materialsare used, the blasting substance 3 is also exploded by the phenomenoncaused in a process of melting and vaporization in the same manner as inthe above embodiment, so that the to-be-blasted object 4 can be securelyblasted or made fragile.

Although according to the above embodiment, the blasting container 6 ismounted in the mounting hole 5 formed in the to-be-blasted object 4, itis permissible, without being restricted to this example, to butt theblasting container 6 to the surface of the to-be-blasted object 4 or tohoist the blasting container with an appropriate hoisting tool so thatit is disposed in the vicinity of the surface of the to-be-blastedobject 4. In any case, by supplying electric energy to the metallic finewire 2 (a small piece of metal or a conductive material such as carbon),the metallic fine wire 2 is melted and vaporized rapidly so that theblasting substance 3 is exploded by the phenomenon accompanying thatprocess. As a result, the to-be-blasted object 4 is blasted and madefragile by the shock caused in the process of melting and vaporizationof the metallic fine wire 2 and the explosive force of the blastingsubstance 3.

Further, by adjusting the blasting force of the blasting apparatus 1 ofthe above embodiment, this blasting apparatus 1 can also be used as afocus apparatus for geophysical prospecting.

INDUSTRIAL APPLICABILITY

As described above, the blasting apparatus of the present invention issuitable for blasting a to-be-blasted object requiring a massiveblasting force.

What is claimed is:
 1. A blasting apparatus in which a material selectedfrom the group consisting of nitromethane and gasoline is filled in ablasting container, a melting/vaporization substance which is melted andvaporized rapidly when an electric energy of a predetermined amount issupplied thereto for a short time is provided in said material so thatsaid melting/vaporization substance is exposed, an electric energysupply circuit for supplying said electric energy to saidmelting/vaporization substance is provided, and said material is capableof being exploded by a phenomenon caused in a process of melting andvaporization of said melting/vaporization substance so as to blast ato-be-blasted object by the explosive force.